The investigation into a January midair collision that killed 67 people near Washington, D.C., revealed an alarming number of recent close calls just outside the nation’s capital.

The NTSB says the current helicopter routes around the busy airport "pose an intolerable risk to aviation safety" in the wake of January's collision that killed 67 people.

More than a month after an American Airlines plane and a Black Hawk helicopter collided near Reagan National Airport (DCA), killing 67 people, officials with the National Transportation Safety Board (NTSB) are calling for immediate changes to helicopter routes around DCA because they said it poses “an intolerable risk to aviation safety.